Tips for adding UVC to commercial pools
By Mary Costello Vandergrift
Experts say every commercial pool operator should consider making an old technology new again.
For years, ultraviolet water treatment has been used to help sterilize drinking water and has been used in wastewater treatment plants. But only in the last handful of years has UVC technology made its way into the commercial pool industry.
It seems like a no-brainer. After all, installing a UVC system at a commercial aquatic facility will lower chemical usage in a pool by up to 30 to 50 percent and can achieve safer water by eliminating pathogens, viruses and chloramines.
So why has it taken so long for the industry to embrace UVC technology? Marty Fisher is the commercial sales manager at Delta UV Ultraviolet Solutions and has worked in the swimming pool and spa market since 1977. He says the use of ultraviolet light is something many people working with commercial pools have known about for a long time. “They may be aware of it, but they don’t understand it,” Fisher says. “One of the things our industry doesn’t do very well is educate itself.”
Fisher says that when a client is educated, UVC technology often sells itself. He says many clients reach out to address chloramines, reduce chemicals or prevent a facility shutdown because of tougher regulations. He also says some clients come in a panic because people got sick after using their facility.
The germicidal energy of ultraviolet light destroys illness-causing microorganisms by attacking the DNA at the genetic core. This eliminates the organisms’ ability to reproduce, rendering them harmless. UV water purification systems eliminate 99.99 percent of the harmful viruses and bacteria like E. coli, fecal contamination or cryptosporidium.
“We’re called secondary sterilization,” Fisher says. “Chlorine is primary because you can adjust it by adding more or less. UV is also compatible with ozone, liquid chlorine, enzymes and just about any other chemical used to sanitize a pool.”
Fisher says every pool professional should be well versed on these aspects of UVC systems:
- Before pool professionals can start selling UV, they need to understand the benefits of UVC and how to select the proper unit for specific aquatic applications. It is important to match the unit size to the pool or water feature type (e.g., splash pad, play structure, lazy river, etc.). By understanding these differences, pool professionals can easily determine which unit to recommend.
- There are two types of UV lamps: low-pressure and high-output lamps. High-output lamps emit UV rays at 254 nanometers (nm), and medium-pressure lamps emit UV rays between 200 and 600 nm.
- Low-pressure lamps are better suited for semicommercial and commercial applications with lower flow rates and light bather loads. Medium-pressure models are designed for large commercial installations with high flow rates and heavy bather loads. The differences between each lamp are cost, flow requirements and the ability to destroy chloramines.
- UVC systems are sized according to the gallons per minute of the pool filtration system, not the volume of water in the vessel. Bigger is not always better when it comes to sizing UV systems. The power rating to look for in a commercial UV unit is 40 MJ (based on NSF50 standard), which will sterilize all pathogens found in swimming pool water.
- UVC units must be installed after the filter. If there is a heater in the system, the preferred location for the UVC unit is before the heater, as the UVC unit has removed chloramines from the water. Because chloramines are corrosive to the metal in the heat exchanger, using a UVC unit on the pool with a heater will extend the life of the heater.
- Most ultraviolet water-treatment systems require only an annual change of lamp — as simple as changing a light bulb — and a periodic change of a filter cartridge that protects the lamp. Although the initial cost of some UV applications are a bit more than chlorination, the low operating costs often make it pay for itself.
Consult an expert to get the correct level of protection for the pool.